Genshin Impact is an open-world action role-playing game developed by miHoYo. Other quests can be navigated or the game will automatically show you where to go, but in this case, you need to find the location of treasure with the help of hints.
Genshin Impact Solve The Mystery Guide
The name of the quest is Secret Pirate Treasure and you have to find the location of the treasure using hints. There will be two hints scattered around the map which you need to locate in order to find the final treasure.
The first hint will be located in the town of Mondstadt on top of the windmill. Refer to the map above to find the exact location of the windmill. Climb on top of it and you will find a treasure box. Open the treasure box to find the next clue.
To find the second hint, you need to first teleport to the Windwail Highland. It is a teleport point in the middle of the lake near the Springvale Waterfall. You need to climb to the top of the waterfall to find three statue-like a pillar with frozen elemental on them.
You need to use Kaeya freezing ability on the statue to activate them. Once they are activated a treasure box will pop up and inside that will be the second hint.
After finding the first two hint, the game will automatically show you the location of the secret pirate treasure which will be inside a cave. You need to go inside the cave and defeat all the enemies. At the end of the cave, you will meet the boss Ruin Guard. Once you have defeated the boss, the secret pirate treasure quest will be completed.